JP5338000B1 - Real-time 3D radiotherapy device - Google Patents

Abstract

By realizing a radiotherapy apparatus capable of irradiating a radiotherapy target with radiation with high accuracy, the radiotherapy period is significantly shortened without impairing treatment quality.
A real-time three-dimensional radiotherapy apparatus according to the present invention includes a first therapeutic radiation detector for detecting beam data of therapeutic radiation before passing through a therapeutic target and radiation after passing through the therapeutic target. A second therapeutic radiation detector 5 for detection is provided, and by using an iris collimator for the collimator 3, irradiation field formation of 1 mm to 50 mm is realized, and the beam data detected by the two detectors is irradiated next. Real-time feedback to conditions enables high-precision radiotherapy.
[Selection] Figure 1

Description

  The present invention relates to a real-time three-dimensional radiation therapy apparatus suitable for IMRT (Intensity Modulated Radiation Therapy). More specifically, the present invention detects beam data such as irradiation field shape, irradiation direction, intensity, dose and dose distribution for each treatment radiation irradiation, and the position and shape of the treatment target, and these results are obtained in real time. The present invention relates to a real-time three-dimensional radiotherapy apparatus that feeds back to the next irradiation condition.

  Radiation therapy is generally performed according to the step flow shown in FIG. A patient undergoing radiotherapy receives a detailed image of the treatment target using an image diagnostic apparatus including a CT scanner in order to identify the treatment target prior to radiotherapy. Based on the captured image data, the doctor formulates a treatment plan to determine irradiation conditions such as the radiation field shape, irradiation direction, intensity, dose, and dose distribution. The prepared treatment plan is verified with respect to the accuracy and validity of the treatment plan by performing a simulation using an X-ray simulator and a measurement evaluation using a phantom before performing radiotherapy. In particular, in the case of IMRT, this combination of irradiation conditions is complicated, so this pre-treatment verification is important. Conventionally, it takes one to two weeks for the preparation period from the imaging by the CT scanner to the end of verification and the start of radiation therapy. Next, it moves to the step of radiation therapy. The patient is fixed in the same position as when the treatment plan was formulated and receives radiation. The number of times of irradiation varies depending on the disease. For example, in the case of prostate cancer, about 20 minutes / times of treatment is divided into 36 to 39 times and continuously performed every day. Therefore, the treatment period takes 7 to 8 weeks. The reason why treatment requires a long period of time is that conventional radiation therapy apparatuses cannot concentrate and irradiate only high doses of radiation that can kill cancer cells with a single irradiation. According to the conventional radiotherapy apparatus, since the resolution of the radiation beam is only about 1 cm, not only the treatment of cancer cells of 1 cm or less, but also the cancer cells and the healthy cells at the boundary part of the cancer cells with high accuracy. Cannot be irradiated. Therefore, a low dose of radiation that does not damage healthy cells must be divided and irradiated many times. By dividing and irradiating in this way, healthy cells can be recovered even after being damaged by radiation, but cancer cells are killed by abnormal division.

  Therefore, the present inventor can follow the movement of the treatment target of the patient in real time, and uses a high-power and thin X-ray beam, and at high speed and high accuracy from all directions along the three-dimensional shape of the treatment target. An X-ray therapy apparatus capable of performing X-ray therapy was filed on March 25, 2009 as the title of the invention "X-ray therapy apparatus" (Japanese Patent Application No. 2009-75008), and patented on December 11, 2009 (Patent No. 4418888: Patent Document 1). The X-ray treatment apparatus described in Patent Document 1 is provided with an X-ray generation source that outputs high energy X-rays of 1 MV or more and continuously changes the beam diameter in the range of 1 mm to 10 mm. With this X-ray generation source, X-rays can be irradiated with high accuracy along the three-dimensional shape of the treatment target. As shown in FIG. 8, the X-ray therapy apparatus described in Patent Literature 1 maintains a facing relationship with the therapy X-ray generator 70 and moves in conjunction with the movement of the therapy X-ray generator 70. A sensor 71 is provided. The therapeutic X-ray sensor 71 is a sensor for detecting X-ray beam data such as the irradiation field, intensity, direction, dose, and dose distribution of the therapeutic X-ray transmitted through the treatment target. Data acquired by this sensor is processed in real time and fed back to the next irradiation condition to perform highly accurate treatment. However, treatment X-ray information is only data after passing through the treatment target, and the dose absorbed by the treatment target must be calculated using treatment plan data. Further, since the irradiation direction of therapeutic X-rays is detected by only one plane, the accuracy is insufficient. Furthermore, since the X-ray treatment apparatus described in Patent Document 1 forms an irradiation field by an X-ray tube array in which a plurality of X-ray tubes that output a thin X-ray beam are bundled, The procedure to form was complicated.

  As described above, conventional radiotherapy requires a long time. Therefore, in order to shorten the entire period of radiotherapy, proposals have been made to shorten verification before radiotherapy.

  The invention described in Patent Document 2 discloses a verification method that does not require measurement evaluation using a conventional phantom. Radiation irradiation is performed toward the two-dimensional transmission detector, and a fluence is calculated by a fluence calculation algorithm based on the detection result and data such as a beam model parameter, a beam model, and a machine parameter set. Next, a three-dimensional dose distribution for the treatment target is acquired using the calculated fluence and the three-dimensional image data including the information on the shape and density of the treatment target and a dose algorithm. However, the three-dimensional dose distribution acquired by the dose algorithm is a calculated dose distribution, and an accurate problem remains. Furthermore, the invention described in Patent Document 2 does not mention any post-treatment verification.

Japanese Patent No. 4418888 Special table 2010-508106 gazette

The prior art described above includes the following problems to be solved.
-In the X-ray treatment apparatus, the X-ray for treatment is detected only by the X-rays that have passed through the treatment target, so the irradiation X-ray beam such as the irradiation field shape, irradiation direction, intensity, dose, and dose distribution The accuracy of the absorbed dose in the data and treatment target is insufficient.
・ The treatment period cannot be shortened without impairing the accuracy of radiotherapy.
-It takes a lot of time and effort to verify the treatment plan and its validity and to verify the treatment results after radiation therapy.

  The object of the present invention is to follow the movement of the treatment target in real time, detect the beam data of the therapeutic radiation with high accuracy, feed back to the next irradiation condition in real time, and perform radiotherapy with high speed and high accuracy. The object is to provide a radiotherapy apparatus suitable for IMRT.

  Furthermore, the objective of this invention is providing the radiotherapy apparatus which can reduce a treatment plan formulation, its data verification, and the verification operation after a treatment significantly.

In order to achieve the above object, a radiotherapy apparatus according to claim 1 according to the present invention comprises:
A therapeutic radiation source attached to the head of the therapeutic radiation source robot;
A collimator for adjusting the shape of the field of therapeutic radiation emitted from the therapeutic radiation source;
A first therapeutic radiation detector and a second therapeutic radiation detector for detecting the therapeutic radiation;
A couch robot that supports the couch on which the patient lies and controls its position and posture;
Two or more position detection X-ray sources attached to the side of the couch or in the vicinity of the couch facing the patient who is supine on the couch;
Two or more position detection X-ray detectors which are attached to the lower side of the couch so as to face the position detection X-ray source and detect the position detection X-rays irradiated toward the marker and / or the treatment target; ,
An image processing device that reconstructs an image of a treatment target and calculates position coordinates of the treatment target based on detection data of the position detection X-ray detector;
A monitor for displaying the output of the image processing device;
A central processing unit for calculating beam data such as intensity, irradiation direction, irradiation field shape, dose and dose distribution of the therapeutic radiation from detection data of the first and second therapeutic radiation detectors;
A storage device for storing output data of the image processing device and the central processing unit;
A radiotherapy apparatus comprising a control device for controlling the therapeutic radiation source robot, the couch robot, the apparatus, and the like,
The first therapeutic radiation detector detects therapeutic radiation irradiated from the therapeutic radiation source and immediately after passing through the collimator;
The second therapeutic radiation detector is disposed in proximity to a couch on which a patient lies while holding a positional relationship opposite to the first therapeutic radiation detector, and is adapted to the movement of the therapeutic radiation source. Follow and move, detect therapeutic radiation transmitted through the treatment target,
The central processing unit uses the output data of the image processing device and the detection data of the first and second therapeutic radiation detectors as input data in real time, the intensity of the therapeutic radiation, the irradiation direction, the dose, the dose distribution, Computation processing related to the absorbed dose in the treatment target, irradiation field shape, treatment target position, etc., and means for feeding back the calculation result in real time to the next irradiation condition of the treatment radiation,
The position detection X-ray source and the position detection X-ray detector facing the X-ray source for position detection maintain a positional relationship facing each other, and the irradiation direction and angle of the position detection X-ray source are supine on the couch It is controlled by a couch robot so as to face the treatment target of the present invention, and an X-ray image of the marker embedded in the vicinity of the treatment target and / or the treatment target itself is captured.

A radiotherapy apparatus according to claim 2 according to the present invention is the radiotherapy apparatus according to claim 1,
The therapeutic radiation source robot is a multi-axis arm robot,
Gantry robot,
C-arm robot, or
Any one of the robots having a C-arm coupled to an arm tip of the multi-axis arm robot, which supports the therapeutic radiation source, the collimator, and the first therapeutic radiation detector. It is characterized by.

A radiotherapy apparatus according to claim 3 according to the present invention is the radiotherapy apparatus according to claim 2,
The second therapeutic radiation detector is supported by a gantry-type robot, a C-arm type robot, or a robot having a C-arm coupled to an arm tip of the multi-axis arm-type robot.

The radiotherapy apparatus according to claim 4 according to the present invention is the radiotherapy apparatus according to claim 1, 2, or 3,
The collimator is an iris collimator.

The radiotherapy apparatus according to claim 5 according to the present invention is the radiotherapy apparatus according to claim 1, 2, or 3,
The radiation irradiated from the therapeutic radiation source is subjected to beam adjustment by the collimator, and as a result, the diameter or width of the irradiation field in the treatment target is 1 mm.

The radiotherapy apparatus according to claim 6 of the present invention is the radiotherapy apparatus according to claim 1, 2, or 3,
Identifying a position and a shape of a marker and / or a treatment target by the position detection X-ray source and the position detection X-ray detector, setting an irradiation condition of the treatment radiation, and the treatment radiation Irradiating therapeutic radiation from a source toward a therapeutic target, obtaining beam data of the therapeutic radiation by the first and second therapeutic radiation detectors, and beam data of the therapeutic radiation. Based on this, the step of updating the next irradiation condition in real time and the step of storing the output data of the position detecting X-ray detector and the first and second therapeutic radiation detectors in the storage device in real time It is characterized by performing.

  The radiotherapy apparatus according to claim 7 of the present invention is the radiotherapy apparatus according to claim 6, wherein the detection data of the position detection X-ray detector and the detection data of the first and second therapeutic radiation detectors are used. When the irradiation condition is updated based on the above, and the irradiation condition is such that the next irradiation region deviates from the treatment target, an automatic stop means for stopping the irradiation of the therapeutic radiation from the therapeutic radiation source is provided.

  The radiotherapy apparatus according to an eighth aspect of the present invention is the radiotherapy apparatus according to the sixth aspect, wherein the X-ray detector for position detection and the first and second therapeutic radiation detections accumulated in the storage device. The detector detection data can be used as verification data for the results of radiotherapy.

  A radiotherapy apparatus according to a ninth aspect of the present invention is the radiotherapy apparatus according to the sixth aspect, characterized in that a repetition period of the irradiation of the therapeutic radiation is 250 times / second.

  According to the above configuration, the movement of the treatment target of the patient is followed in real time, the beam data of the treatment radiation and the position and shape of the treatment target are detected and fed back to the next irradiation condition in real time for high speed and high accuracy. A radiotherapy apparatus suitable for IMRT that can perform radiotherapy can be provided. By using this radiotherapy apparatus, it is possible to irradiate a high dose of radiation to a treatment target with high accuracy, and the number of times of irradiation can be greatly reduced.

  Furthermore, according to the above configuration, the position and shape of the therapeutic radiation beam data and the treatment target are detected in real time, and the result is fed back to the next irradiation condition to realize high-accuracy radiotherapy, The treatment plan development and its verification and post-treatment verification can be reduced, and the treatment period can be greatly shortened.

It is a block diagram which shows embodiment of the radiotherapy apparatus by this invention. It is a block diagram which shows other 1st Embodiment of the radiotherapy apparatus by this invention. It is a block diagram which shows other 2nd Embodiment of the radiotherapy apparatus by this invention. It is a figure explaining the detection of the radiation of the radiotherapy apparatus by this invention. It is the schematic of the iris collimator used with the radiotherapy apparatus by this invention. It is a flowchart which shows the treatment procedure using the radiotherapy apparatus by this invention. It is a timing diagram which shows the operation | movement timing of the radiotherapy apparatus by this invention. It is a block diagram which shows embodiment of the X-ray therapy apparatus by a prior art. It is a flowchart which shows the treatment procedure using the radiotherapy apparatus by a prior art.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. In the drawings, the same functions are denoted by the same reference numerals. FIG. 1 is a block diagram showing an embodiment of a radiotherapy apparatus according to the present invention. The robot head 1 is supported by a multi-axis arm robot 10 such as 6-axis or 7-axis. The robot head 1 includes a therapeutic radiation source 2 that generates therapeutic radiation, a collimator 3 that adjusts the irradiation field of the irradiated radiation, and a first therapeutic radiation detector 4 that detects the radiation that has passed through the collimator 3. Built in. In the case of X-rays, the energy of radiation emitted from the therapeutic radiation source 2 is about 6 MV. As shown in FIG. 1, the collimator 3 and the first therapeutic radiation detector 4 are arranged close to the therapeutic radiation source 2, and their effective planes are the central axes of radiation emitted from the therapeutic radiation source 2. It is fixed at an angle perpendicular to 17. The couch robot 11 supports the couch 9, moves the couch 9 in the X, Y, and Z axis directions, rotates about the Z axis, and controls the inclination with respect to the X axis and the Y axis. Position detection X-ray sources 7L and 7R are mounted on both sides of the couch 9. The position detection X-ray sources 7L and 7R may be installed on the side of the couch or in the vicinity of the couch 9 that can be controlled by the couch robot 11. The X-rays emitted from the position detection X-ray sources 7L and 7R are low energy X-rays of about 100 kV. A position detection X-ray detector 8R facing the position detection X-ray source 7L and a position detection X-ray detector 8L facing the position detection X-ray source 7R are respectively mounted on the lower side of the couch. . The position detection X-ray detectors 8L and 8R may be installed under the couch 9 or in the vicinity of the couch that can be controlled by the couch robot 11. The position detection X-ray sources 7L and 7R are arranged at right angles or other angles so that the emitted X-rays intersect at the treatment target. This crossing angle is appropriately set by the couch robot 11 according to the condition of the treatment target. Movement control of the positions, directions, and the like of the position detection X-ray sources 7L and 7R and the position detection X-ray detectors 8L and 8R is performed by the couch robot 11 in accordance with a signal from the control device 12. The means for moving the irradiation fields of the position detection X-ray sources 7L and 7R according to the position of the treatment target can be realized by a configuration in which only the couch 9 on which the patient lies is moved. As another means, the couch 9 can be fixed, and can be realized by a configuration in which the position detection X-ray sources 7L and 7R and the position detection X-ray detectors 8L and 8R are controlled to face the treatment target. 9 and the position detecting X-ray sources 7L and 7R and the position detecting X-ray detectors 8L and 8R can also be realized.

  Below the couch 9, the second therapeutic radiation detector 5 is supported by the couch robot 11 and is disposed opposite the first therapeutic radiation detector 4. A tungsten beam stopper 6 for absorbing therapeutic radiation is disposed on the back side of the second therapeutic radiation detector 5. The beam stopper 6 is arranged so as to be interlocked with the second therapeutic radiation detector 5. The facing relationship between the first and second therapeutic radiation detectors 4 and 5 is maintained by the arm robot 10 and the couch robot 11 in accordance with a signal from the control device 12. FIG. 4 shows the positional relationship among the therapeutic radiation source 2, the collimator 3, the first therapeutic radiation detector 4, the second therapeutic radiation detector 5, and the beam stopper 6. The collimator 3, the first therapeutic radiation detector 4, the second therapeutic radiation detector 5, and the beam stopper 6 have a respective effective plane with respect to the central axis 17 of the radiation emitted from the therapeutic radiation source 2. It is controlled by a signal from the control device 12 so as to maintain the vertical positional relationship. In IMRT, radiation is emitted from all three directions toward the treatment target 18. The first therapeutic radiation detector 4 and the second therapeutic radiation detector 5 are controlled so as to always maintain an opposing relationship across the treatment target 18. Therefore, when the irradiation is performed from the back side of the patient, that is, from the lower side of the couch 9, the second therapeutic radiation detector 5 and the beam stopper 6 move to the upper side of the patient.

  The first therapeutic radiation detector 4 can be realized by using a normal optical fiber or scintillation fiber that transmits radiation. By detecting light emitted when radiation is incident on the fiber by a photodiode or a photomultiplier tube, identification of the incident position of the radiation and radiation intensity, dose, and dose distribution can be measured in real time. As the first therapeutic radiation detector 4, a transmission ionization chamber and a semiconductor detector can also be applied. As the second therapeutic radiation detector 5, a flat panel sensor can be suitably used. High-speed, high-resolution flat panel sensor products are commercially available and popular. Further, if a photon sensor is used as the second therapeutic radiation detector 5, higher speed and higher accuracy can be realized. A flat panel sensor is also suitable for the position detection X-ray detectors 8L and 8R. The purpose of the position detection X-ray detectors 8L and 8R is to identify the position and shape of the marker embedded in or near the treatment target, and it is not always necessary to scan all the pixels of the flat panel sensor. Higher speed operation can be achieved by thinning out scan pixels as appropriate.

The collimator 3 adjusts the beam diameter of the radiation emitted from the therapeutic radiation source 2. With recent advances in medical technology, small cancers with a diameter of 1 cm or less have been discovered. In order to treat such a small cancer, it is necessary to narrow the beam diameter of the radiation sufficiently smaller than the size of the cancer at the treatment target. This is to avoid the influence of penumbra that occurs because therapeutic high energy radiation reflects off the inner wall of the collimator or penetrates the edge of the collimator opening. For example, for a cancer with a diameter of 1 cm, the beam diameter of the radiation is preferably at least about 1 mm in diameter. In this way, the radiation having a small beam diameter can form a sharp irradiation field edge. Conventionally, a multi-leaf collimator that has been widely used has a limit of about 8 mm as a minimum beam diameter on a treatment target due to a limitation on leaf thickness. Moreover, the shape was angular. For this reason, a cancer having a size of about 1 cm and a curved shape could not be treated. FIG. 5A shows a schematic perspective view of an iris collimator 30 suitable for the radiotherapy apparatus of the present invention. FIG. 5B shows the opening surface. In FIG. 5A and FIG. 5B, the case where the diaphragm leaves 30a, 30b,..., 30f are six is shown, but the number of leaves may be changed as appropriate. The size of the hole of the opening of the iris collimator is a linear slide attached to the side of the outer peripheral side where the leaves indicated by 30a, 30b,..., 30f in FIG. It can be adjusted by sliding (not shown) in the direction of the arrow. When the radiation is incident on the aperture surface of the iris collimator, the focused radiation is emitted from the other aperture surface side. During radiation treatment, the iris collimator 30 can be squeezed or opened in accordance with the shape of the treatment target, so that radiation can be accurately irradiated along the shape of the treatment target. By using the iris collimator 30, the irradiation field of the therapeutic radiation can be adjusted to 1 to 50 mm in diameter at the treatment target. The material of the iris collimator is a heavy metal that absorbs radiation, such as tungsten.

  The central processing unit 14 and the image processing unit 15 use the DLT (Direct Linear Transformation) method or the like from the output data of the position detection X-ray detectors 8L and 8R to convert the treatment target or marker from the two-dimensional coordinates to the three-dimensional coordinates. Ask for. Further, the projection data is reconstructed and converted into a three-dimensional image. The practitioner can display a three-dimensional image of the marker or treatment target on the monitor 16 and confirm the position and shape. The central processing unit 14 and the image processing unit 15 process the detection data of the first and second therapeutic radiation detectors 4 and 5 as input data, and the intensity of the therapeutic radiation, the irradiation direction, and the shape of the irradiation field. Output radiation data of therapeutic radiation such as dose and dose distribution and position and shape data of the treatment target. The radiotherapy apparatus of the present invention acquires the beam data of the radiation immediately after being radiated from the collimator 3 by the first therapeutic radiation detector 4 and passes through the treatment target by the second therapeutic radiation detector 5. Since the radiation beam data is acquired, it is possible to know the detailed absorbed dose in the treatment target as compared with the conventional radiotherapy apparatus. Furthermore, since the next irradiation condition can be corrected and updated for each irradiation of therapeutic radiation based on the beam data detected by the first and second therapeutic radiation detectors 4 and 5, On the other hand, accurate irradiation is possible. As described above, the radiation therapy apparatus of the present invention can accurately irradiate with a thin radiation beam, so that damage to a healthy tissue can be greatly reduced as compared with a conventional radiation therapy apparatus. Therefore, the treatment target can be irradiated with a high dose of radiation, so that treatment can be completed with only one irradiation compared to the conventional treatment with a radiotherapy device divided into 30 or more irradiations. Is possible. Thus, according to the radiotherapy apparatus of the present invention, the period of radiotherapy can be significantly shortened compared to the conventional radiotherapy apparatus, and the burden on patients and doctors can be greatly reduced. . Furthermore, treatment costs can be reduced.

  FIG. 2 shows another first example in which the therapeutic radiation source 2, collimator 3, first therapeutic radiation detector 4, and second therapeutic radiation detector 5 of the radiotherapy apparatus of the present invention are mounted on a gantry robot. The embodiment of is shown. In FIG. 2, the robot head 1 incorporating the therapeutic radiation source 2, the collimator 3, and the first therapeutic radiation detector 4 is attached to the rotating unit 21 of the gantry robot 20. The second therapeutic radiation detector 5 and the beam stopper 6 are also arranged on the rotating unit 21 so as to face the robot head 1. The rotating unit 21 rotates around the treatment target about the X axis as a central axis while maintaining the facing relationship between the robot head 1 and the second therapeutic radiation detector 5. According to the present embodiment, the radiation is irradiated from all angles to the treatment target by the rotation of the rotating unit 21 and the swinging motion of the robot head 1.

  FIG. 3 shows another treatment radiation source 2, collimator 3, first treatment radiation detector 4, and second treatment radiation detector 5 of the radiation treatment apparatus of the present invention mounted on a C-arm robot. 2 shows an embodiment. In FIG. 3, the robot head 1 incorporating the therapeutic radiation source 2, the collimator 3 and the first therapeutic radiation detector 4, the second therapeutic radiation detector 5 and the beam stopper 6 are opposed to both ends of the C arm 22a. It is installed in a relationship. Therefore, even if the C-arm 22a moves while rotating around the patient, the first and second therapeutic radiation detectors 4 and 5 can always maintain the facing relationship. As another embodiment, even if the present invention is applied to a robot in which the C-arm portion shown in FIG. 3 is attached to the tip of the arm-type robot 10 and couch robot 11 as shown in FIG. The same effects as those of the embodiment and the other second embodiment of FIG. 3 are expected.

  FIG. 6 shows steps in the case of performing radiotherapy using the radiotherapy apparatus of the present invention. First, the doctor formulates a radiation treatment plan (step group 40). In conventional treatment planning, a treatment target is imaged in detail by an image diagnostic apparatus including a CT scanner. Thereafter, a doctor determines detailed treatment methods and conditions such as setting of a treatment target, irradiation direction, intensity, irradiation field shape, dose, and dose distribution of treatment radiation based on the captured image. At this time, it must be considered that the treatment target moves due to breathing or the like. In contrast, when using the radiotherapy apparatus of the present invention, the doctor basically performs the CT scanner imaging (step 41) to set the treatment target, and then basically sets the treatment target. It is only necessary to determine the radiation irradiation point, irradiation direction, intensity, dose, and dose distribution (step 42). The reason why the treatment plan can be simplified in this manner is that, as shown in the radiation treatment step (step group 50), the beam data of the treatment radiation and the treatment target irradiated by the central processing unit 14 every time the treatment radiation is emitted. This is because the position and shape are detected and analyzed in real time to determine the validity of the irradiation result and feed back to the next irradiation condition.

  In the conventional IMRT treatment plan formulation, before implementing the formulated treatment plan, the validity of the absorbed dose of the treatment target is measured by simulation using a simulator or by actually measuring the irradiation dose using a phantom. It is necessary to verify the validity. On the other hand, when using the radiotherapy apparatus of the present invention, the preliminary verification can be basically omitted. The reason for this is that, as described above, while repeating the position detection X-ray and the irradiation of the therapeutic radiation, the central processing unit 14 analyzes the position and shape data of the target and the beam data of the therapeutic radiation for each irradiation in real time, This is because feedback is appropriately applied to the next irradiation condition. Accordingly, each therapeutic radiation is always accurately performed under optimum irradiation conditions. As described above, when the radiotherapy apparatus of the present invention is used, it is possible to greatly shorten the treatment plan formulation and the subsequent verification period. This can greatly reduce the burden on the doctor.

  Next, actual radiation therapy is performed (step group 50). The step group 50 will be described with reference to FIG. 6 and FIG. 7 showing a timing chart of main steps of radiation therapy. In conventional IMRT, it is necessary to align the position of the treatment target of the patient who is supine on the couch with the position at the time of treatment planning before performing radiation therapy. On the other hand, when the radiotherapy apparatus of the present invention is used, alignment of the treatment target is not necessary. When the radiotherapy apparatus of the present invention is used, immediately before the therapeutic radiation is irradiated, X-rays having lower energy than the position detection X-ray sources 7L and 7R are irradiated toward the treatment target and embedded in the vicinity of the treatment target. Imaging of the marker and / or the treatment target itself. The position detection X-ray sources 7L and 7R and the position detection X-ray detectors 8L and 8R are controlled by the couch robot 11, and the position coordinates and shape of the treatment target are determined in real time in an independent three-dimensional coordinate system on the couch. Identify. The imaging data and position data of the treatment target detected by the position detection X-ray detectors 8L and 8R are subjected to image processing by the image processing device 15 and reconstructed into a three-dimensional image. As an algorithm for image reconstruction processing, a filtered back projection method capable of high-speed processing is suitable. In this way, the three-dimensional position coordinates and the shape of the treatment target are identified in real time (step 51). The irradiation condition of the first therapeutic radiation is set based on the treatment plan data (step 52). After the first therapeutic radiation is irradiated (step 53), the irradiated therapeutic radiation is detected by the first and second therapeutic radiation detectors 4 and 5. The detected data is the beam data of the treatment radiation before and after passing through the treatment target. Based on this data, the dose and the dose distribution absorbed by the treatment target by the central processing unit 14 are calculated. The Further, the first and second therapeutic radiation detectors 4 and 5 detect the intensity, irradiation field shape, and irradiation direction of the irradiated therapeutic radiation. In the radiotherapy apparatus of the present invention, the first and second therapeutic radiation detectors 4 and 5 detect the radiation irradiated at two locations, so that the accurate irradiation direction of the therapeutic radiation and the irradiation field in the treatment target are detected. The shape can be calculated. These data processes can realize a processing speed of 1 ms to 2 ms by using a high-speed CPU, GPU and high-speed memory. Data processed in real time by the central processing unit 14 is sequentially written in the storage unit 13 (step 54).

  Subsequently, for the second irradiation of therapeutic radiation, low-energy X-rays are irradiated toward the treatment target, and the marker embedded in the vicinity of the treatment target and / or the treatment target itself is imaged. The position detection X-rays are repeatedly irradiated at a time interval of 4 ms with a time width of 0.5 μs. The imaged X-rays are detected by the position detection X-ray detectors 8L and 8R. Since the imaging of the marker embedded in the vicinity of the treatment target and / or the treatment target itself and the processing of the detection data are executed in real time with a repetition period of 4 ms, it is sufficient for the movement of the treatment target due to patient respiration and the like. Can follow. Therefore, the position and shape of the treatment target can be accurately captured in each treatment radiation irradiation. The detected imaging data and position data are subjected to image processing in real time by the image processing device 15 to reconstruct a three-dimensional image. The image-processed data is written to the storage device 13 (step 55). Next, based on the initial treatment radiation intensity, radiation field shape, radiation direction, dose and dose distribution beam data, treatment target absorbed dose data and treatment target position and shape data, The next irradiation condition is set by the processing device 14 (step 56). Subsequently, the second therapeutic radiation is irradiated (step 57). Standard therapeutic radiation is performed 250 times per second. The therapeutic radiation is irradiated with a time width of 4 μs, and is repeated at a time interval of 4 ms. The irradiated therapeutic radiation is detected by the first and second therapeutic radiation detectors 4 and 5. The detected data is processed in real time by the central processing unit 14 and the image processing unit 15 as described above, and the irradiation field shape, irradiation direction, dose and dose distribution data, treatment target absorbed dose data, and the like are output. Is done. These data are sequentially written to the storage device 13 (step 58). Next, the central processing unit 14 determines whether or not to end radiotherapy (step 59). If the radiotherapy has not yet been completed for the entire region of the treatment target, the process returns immediately before step 55, and steps 55 to 59 are repeated. In step 59, if the central processing unit 14 determines that radiotherapy has been completed for the entire area of the treatment target, the radiotherapy is automatically terminated. Further, in the course of radiation therapy, due to the failure of the therapeutic radiation source robot such as the arm robot 10 or the couch robot 11 or the sudden movement of the treatment target, the area deviates from the preset therapeutic area. When radiation is to be irradiated, the radiation irradiation is automatically stopped based on the determination by the central processing unit 14.

  After the radiotherapy is completed, it is important for the doctor to verify the treatment result in order to use it as reference data for the subsequent radiotherapy. As shown in Patent Document 2, the radiation beam data acquired in the conventional radiotherapy apparatus is only the radiation data before passing through the treatment target. Therefore, the dose absorbed by the treatment target with respect to the radiation for each irradiation cannot be obtained accurately. Moreover, the X-ray therapy apparatus described in Patent Document 1 by the present inventor includes a detector (therapeutic X-ray sensor 71) that detects X-rays that have passed through the therapy target. Therefore, although X-ray beam data after passing through the treatment target can be acquired, there is no X-ray beam data before passing through the treatment target, so accurate absorbed dose data cannot be acquired immediately. Since the radiotherapy apparatus according to the present invention includes the first and second therapeutic radiation detectors 4 and 5, it is possible to acquire radiation beam data before and after transmission through the treatment target for each irradiation. . With these data, an accurate irradiation direction, intensity, dose, absorbed dose, dose distribution, irradiation field shape, and the like can be acquired for each irradiation. In addition, since these data are processed in real time immediately after detecting the radiation and are sequentially stored in the storage device 13, the processing of the data is much easier than before. This greatly reduces the burden of post-treatment verification by the doctor.

  As described above in detail, according to the real-time three-dimensional radiotherapy apparatus of the present invention, the first and second therapeutic radiation detections are performed before and after the therapeutic radiation passes through the treatment target, respectively. Since the beam data of the therapeutic radiation is acquired by the devices 4 and 5, it is possible to accurately know the irradiation state and the treatment state of the radiation. The diameter or width of the irradiation field shape of the therapeutic radiation can be adjusted over a wide range of 1 mm to 50 mm by the iris collimator, so that the treatment target can be accurately irradiated without damaging healthy cells. As a result, it is possible to irradiate a high dose of therapeutic radiation at a time, and there is no need to perform divided irradiation as in the prior art. Since data processing during radiation therapy is executed in real time, it is possible to accurately irradiate the treatment target with radiation following the movement of the treatment target. Since the capture and irradiation of the treatment target can be repeated in real time, it is not necessary to develop a conventional detailed treatment plan, and further, it is not necessary to verify the treatment plan before treatment. Verification after treatment can be easily performed at any time based on radiation beam data accumulated during the treatment. As described above, by applying the real-time three-dimensional radiotherapy apparatus according to the present invention, high-accuracy radiotherapy can be performed, and further, the radiotherapy period can be greatly shortened, greatly increasing the burden on patients and doctors. Can be reduced. As a result, the cost of radiation therapy can be reduced.

  It is a medical device used for treatment of tumors in medical facilities such as hospitals.

DESCRIPTION OF SYMBOLS 1 Radiation robot head 2 Therapeutic radiation source 3 Collimator 4 The 1st therapeutic radiation detector 5 The 2nd therapeutic radiation detector 6 Beam stopper 7L X-ray source for position detection 7R X-ray source for position detection 8L For position detection X-ray detector 8R X-ray detector for position detection 9 Couch 10 Arm type robot 11 Couch robot 12 Controller 13 Storage device 14 Central processing unit 15 Image processing unit 16 Monitor 17 Radiation central axis 18 Treatment target 20 Gantry type robot 21 Gantry-type robot rotating unit 22 C-arm robot 22a C-arm 30 Iris collimator 40 Treatment plan formulation step group 50 Radiation treatment step group 60 Post-radiation treatment verification step 70 Treatment X-ray generator 71 Treatment X-ray sensor

Claims (9)

A therapeutic radiation source attached to the head of the therapeutic radiation source robot;
A collimator for adjusting the shape of the field of therapeutic radiation emitted from the therapeutic radiation source;
A first therapeutic radiation detector and a second therapeutic radiation detector for detecting the therapeutic radiation;
A couch robot that supports the couch on which the patient lies and controls its position and posture;
Two or more position detection X-ray sources attached to the side of the couch or in the vicinity of the couch facing the patient who is supine on the couch;
Two or more position detection X-ray detectors which are attached to the lower side of the couch so as to face the position detection X-ray source and detect the position detection X-rays irradiated toward the marker and / or the treatment target; ,
An image processing device that reconstructs an image of a treatment target and calculates position coordinates of the treatment target based on detection data of the position detection X-ray detector;
A monitor for displaying the output of the image processing device;
At least the intensity of the therapeutic radiation from the detection data of the first and second therapeutic radiation detector, the radiation direction, the irradiation field shape, a central processing unit for calculating the beam data of dose and dose distribution,
A storage device for storing output data of the image processing device and the central processing unit;
A radiation therapy device having a control device for controlling the couch robot and the equipment and the therapeutic radiation source robot,
The first therapeutic radiation detector detects therapeutic radiation irradiated from the therapeutic radiation source and immediately after passing through the collimator;
The second therapeutic radiation detector is disposed in proximity to a couch on which a patient lies while holding a positional relationship opposite to the first therapeutic radiation detector, and is adapted to the movement of the therapeutic radiation source. Follow and move, detect therapeutic radiation transmitted through the treatment target,
The central processing unit receives at least the intensity, irradiation direction, dose, and dose distribution of the therapeutic radiation in real time using the output data of the image processing device and the detection data of the first and second therapeutic radiation detectors as input data. , absorbed dose in the treatment target performs irradiation field shape and about the position of the treatment target computing comprises means for feeding back in real time the calculation results in the following irradiation conditions of the therapeutic radiation,
The position detection X-ray source and the position detection X-ray detector facing the X-ray source for position detection maintain a positional relationship facing each other, and the irradiation direction and angle of the position detection X-ray source are supine on the couch A radiotherapy apparatus, which is controlled by a couch robot so as to face the treatment target of the patient and captures an X-ray image of a marker embedded in the vicinity of the treatment target and / or the treatment target itself. The radiotherapy apparatus according to claim 1, wherein
The therapeutic radiation source robot is a multi-axis arm robot,
Gantry robot,
C-arm robot, or
Any one of the robots having a C-arm coupled to an arm tip of the multi-axis arm robot, which supports the therapeutic radiation source, the collimator, and the first therapeutic radiation detector. A radiotherapy apparatus characterized by the above. The radiotherapy apparatus according to claim 2, wherein
The second therapeutic radiation detector is supported by a gantry robot, a C-arm robot, or a robot in which a C-arm is coupled to an arm tip of the multi-axis arm robot. . The radiotherapy apparatus according to claim 1, 2 or 3,
The collimator, I Oh iris collimator, radiation is irradiated onto the aperture plane of the iris collimator, radiation squeezed from the other opening surface side is radiated, during radiation therapy, therapy targeting aperture of the iris collimator to match the in shape, said leaf throttle of iris collimator, squeezed by or or opened, the radiotherapy apparatus according to claim Rukoto can accurately irradiate the radiation along the shape of the therapeutic targets . The radiotherapy apparatus according to claim 1, 2 or 3,
The radiation treatment apparatus according to claim 1, wherein the radiation irradiated from the therapeutic radiation source is beam-adjusted by the collimator, so that the diameter or width of the irradiation field in the treatment target is 1 mm. The radiotherapy apparatus according to claim 1, 2 or 3,
Identifying a position and a shape of a marker and / or a treatment target by the position detection X-ray source and the position detection X-ray detector, setting an irradiation condition of the treatment radiation, and the treatment radiation Irradiating therapeutic radiation from a source toward a therapeutic target, obtaining beam data of the therapeutic radiation by the first and second therapeutic radiation detectors, and beam data of the therapeutic radiation. Based on this, the step of updating the next irradiation condition in real time and the step of storing the output data of the position detecting X-ray detector and the first and second therapeutic radiation detectors in the storage device in real time A radiation therapy apparatus characterized by being executed. The radiotherapy apparatus according to claim 6, wherein
When the irradiation condition is updated based on the detection data of the X-ray detector for position detection and the detection data of the first and second therapeutic radiation detectors, and the irradiation condition in which the next irradiation region is out of the treatment target, A radiotherapy apparatus comprising automatic stop means for stopping irradiation of therapeutic radiation from the therapeutic radiation source. The radiotherapy apparatus according to claim 6, wherein
Radiation therapy apparatus characterized in that detection data of the position detection X-ray detector and the first and second treatment radiation detectors stored in the storage device can be used as data for verification of radiation treatment results. . The radiotherapy apparatus according to claim 6, wherein
The radiotherapy apparatus characterized in that the repetition period of irradiation of the therapeutic radiation is 250 times / second.